Have you got a 24v feed to the SOLENOID from the battery [usually connected to battery positive terminal]? if not there may be a mega fuse fitted in this lead which may have blown. Make sure that tail lift motor has a good earth/earth return connection.
Just a thought: is this vehicle new to you and is cab tail lift isolator switch "on" and supplying live feed to power pack?
sdvsadfg, May 2022
